Traditional Chinese timekeeping

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Explanatory Chart for Chinese time

The traditional Chinese time systems refers to the time standards for divisions of the day used in China until the introduction of the Shixian calendar at the beginning of the Qing dynasty.[1] [2]

Han-era system[edit]

The third chapter of the Huainanzi outlines 15 hours during daylight. These are dawn (晨明), daybreak (), morning (), early meal (; ), feast meal (), before noon (), noon (正中), short shadow (; ), evening (𫗦时; 餔時), long shadow (; 大還), high setting (), lower setting(), sunset (; ), twilight (黄昏; 黃昏), rest time (). [3] These are correlated to each hour from 06:00 to 20:00 on the 24-hour clock.

East Han to Ming system[edit]

This system used two standards to measure the time in a solar day. Times during daylight were measured in the Shí-kè standard, and at night were measured using the Gēng-diǎn standard.

Stems & Branches in traditional Chinese time
Heavenly stems Earthly branches
Stem Gēng Branch Shí
1 jiǎ 19:12 yīgēng 1 00:00 23:00
2 21:36 èrgēng 2 chǒu 02:00 01:00
3 bǐng 00:00 sāngēng 3 yín 04:00 03:00
4 dīng 02:24 sìgēng 4 mǎo 06:00 05:00
5 04:48 wǔgēng 5 chén 08:00 07:00
6 07:12 morning 6 10:00 09:00
7 gēng 09:36 midmorning 7 12:00 11:00
8 xīn 12:00 noon 8 wèi 14:00 13:00
9 rén 14:24 late afternoon 9 shēn 16:00 15:00
10 guì 16:48 evening 10 yǒu 18:00 17:00
11 20:00 19:00
12 hài 22:00 21:00

During daylight: Shí-kè[edit]

The Shí-kè ( - ) system is derived from the position of the sun.

Dual hour: Shí[edit]

Each shí (; ) was ​112 of the time between one midnight and the next,[2] making it roughly double the modern hour. These dual hours are named after the earthly branches in order, with midnight in the first shí. This first shí traditionally occurred from 00:00 to 02:00 on the 24-hour clock, but was changed during the Song dynasty so that it fell from 23:00 to 01:00.[2]

Starting from the end of the Tang Dynasty, each shí was divided into two, with the first half of each shí called the initial hour () and the second called the central hour ().[2] Using the change of the midnight hour and the first shí above, you could say that midnight went from the initial hour of the first shí () to the central hour of the first shí ().

One-hundredth of a day: Kè[edit]

Days were also divided into smaller units, called (). One was usually defined as ​1100 of a day until 1628, though there were short periods before then where days had 96, 108 or 120 .[2] literally means "mark" or "engraving", referring to the marks placed on sundials[4] or water clocks[5] to help keep time.

Using the definition of as ​1100 of a day, each is equal to 0.24 hours, 14.4 minutes, or 14 minutes 24 seconds. Every shí will contain 8​13 , with 7 or 8 full and partial beginning and/or ending . These fractional are multiples of ​16 , or 2 minutes 24 seconds.[a] The 7 or 8 full within each shí were referred to as "major " (大刻). Each ​16 of a was called a "minor " (小刻).[6]

Describing the time during daylight[edit]

Both shí and would be used to describe the time accurately. There are two ways of doing this.

  1. Eight mode. Before the Tang dynasty, the shí were noted first, then each of the major were counted up to 8.[citation needed]
    1. As an example, counting by from the first shí to the second would look like this: zǐ shí, zǐ shí 1 kè, zǐ shí 2 kè, zǐ shí 3 kè, zǐ shí 4 kè, zǐ shí 5 kè, zǐ shí 6 kè, zǐ shí 7 kè, zǐ shí 8 kè, chǒu shí.
    2. Given the time Xū shí 1 kè, this would be read as "eleventh shí + 1 ", making the time 20:09:36.
  2. Four mode. After the Song dynasty, the shí was still noted first, but then a descriptor of whether it was the initial or central hour was added. Since this narrowed the range of the possible major down to four, it was only necessary to specify the between one and four.[citation needed]
    1. This would change our first example above to look like this: zǐ shí, zǐ shí initial, 1 kè , zǐ shí initial, 2 kè, zǐ shí intial, 3 kè, zǐ shí intial, 4 kè (or zǐ shí central) zǐ shí central, 1 kè, zǐ shí central, 2 kè, zǐ shí central, 3 kè, zǐ shí central, 4 kè, chǒu shí.
    2. Given sì shí central, 3 kè, this would be read as "one hour and 3 after ", making the time 11:31:12.

Smaller time units[edit]


were subdivided into smaller units, called fēn (). The number of fēn in each varied over the centuries,[2] but a fēn was generally defined as ​16000 of a day. [6] Using this definition, there are 60 fēn in a ​1100-day major , and a fēn is ​160 of a major . In a minor , there are only 10 fēn. One fēn is equal to 14.4 seconds.


In 1280, Guo Shoujing's Shòushí Calendar (授时曆) calendar subdivided each fēn into 100 miǎo ().[7]. Using the definition of fēn as 14.4 seconds, each miǎo was 144 milliseconds long.

Shùn & Niàn[edit]

Each fen was subdivided into shùn (), and shùn were subdivided into niàn ().

The Mahāsāṃghika, translated into Chinese as the Móhēsēngzhī Lǜ (Taishō Tripiṭaka 1425) describes several units of time, including shùn or shùnqǐng (; "blink moment") and niàn. According to this text, niàn is the smallest unit of time at 18 milliseconds and a shùn is 360 milliseconds.[8] It also describes larger units of time, including a tánzhǐ () which is 7.2 seconds long, a luóyù () which is 2 minutes 24 seconds long, and a xūyú (), which is ​130 of a day at 48 minutes long.[b]

During night: Gēng-diǎn system[edit]

The Gēng-diǎn ( - ) system uses predetermined signals to define the time during the night.

One-tenth of a day: Gēng[edit]

Gēng () is a time signal given by drum or gong. The drum was sounded by the drum tower in city centers, and by night watchman hitting a gong in other areas.[citation needed] The character for gēng , literally meaning "rotation" or "watch", comes from the rotation of watchmen sounding these signals.

The first gēng theoretically comes at sundown, but was standardized to fall at 1 kè, a.xū shí, or 19:12. The time between gēng is ​110 of a day, coming every 2.4 hours, or 2 hours 24 minutes.

The 5 gēngs in the night are numbered from one to five: yī gēng () (alternately chū gēng (初更) for "initial watch"); èr gēng (二更); sān gēng (三更); sì gēng (四更); and wǔ gēng (五更). The 5 gēngs in daytime are named after times of day listed in the Book of Sui, which describes the legendary Yellow Emperor dividing the day and night into ten equal parts. They are morning (); midmorning, (); noon, (); afternoon (); and evening (). [9]

As a 10-part system, the gēng are strongly associated with the 10 celestial stems, especially since the stems are used to count off the gēng during the night in Chinese literature.[9]

One-sixtieth of a day: Diǎn[edit]

Diǎn (; ), or point, marked when the bell time signal was rung. The time signal was released by the drum tower or local temples.[citation needed]

Each diǎn or point is ​160 of a day, making them 0.4 hours, or 24 minutes, long. Every sixth diǎn falls on the gēng, with the rest evenly dividing every gēng into 6 equal parts.

Describing the time during the night[edit]

Gēng and diǎn were used together to precisely describe the time at night.

Counting from the first gēng to the next would look like this: yīgēng, yīgēng 1 diǎn, yīgēng 2 diǎn, yīgēng 3 diǎn, yīgēng 4 diǎn, yīgēng 5 diǎn, èrgēng.
Given the time sāngēng 2 diǎn, you would read it as "two diǎn after sāngēng", and find the time to be 00:48[c].

The night length is inconsistent during a year. At the winter solstice, a day is 60% night, and at the summer solstice, a day is only 40% night. The official start of night will thus vary from 0 to 1 gēng. In practice, yīgēng is postponed for ​51000 of a day every 9th day from the winter solstice to the summer solstice, and moved up ​51000 of a day every 9th day from summer solstice to the winter solstice.[10]

Modern applications[edit]

Chinese still uses characters from these systems to describe time, even though China has changed to the UTC standards of hours, minutes, and seconds.

Shí is still used to describe the hour. Because of the potential for confusion, xiǎoshí (小时; 小時, literally "small hour") is sometimes used for the hour as part of a 24-hour cycle, and shíchen (时辰; 時辰) is used for the hour as part of the old 12-hour cycle.

Diǎn is also used interchangeably with shí for the hour. It can also be used to talk about the time on the hour—for example, 8 o' clock is written as 8 diǎn (八点; 八點).

Fēn is also used for minutes. To avoid confusion, sometimes the word fēnzhōng (分钟; 分鐘, literally "clock minute") is used to clarify that one is talking about modern minutes. The time 09:45 can thus be written as "9 shí, 45 fēn" (四十五; 四十五) or "9 diǎn, 45 fēn" (四十五; 四十五).

has been defined as ​196 of a day since 1628, so the modern equals 15 minutes and each double hour contains exactly 8 .[2] Since then, has been used as shorthand to talk about time in ​18 of a double hour or ​14 of a single hour. Their usage is similar to using "quarter hour" for 15 minutes or "half an hour" for 30 minutes in English. For example, 6:45 can be written as "6 diǎn, 3 " (六点; 六點).

Miǎo is now the standard term for a second.

See also[edit]


  1. ^ 600 is the LCM of 100 and 24, so the time between and shí scale may be ​16, ​13, ​12, ​23, or ​56 major . The ​16 major is the common factor
  2. ^ This 30-part day is identical to the Hindu muhūrta.
  3. ^ This assumes that the diǎn haven't moved; or if they have, that sāngēng still falls at exactly midnight.


  1. ^ K. Yabuuti [Kiyoshi Yabuuchi], "Astronomical tables in China, from the Wutai to the Ch'ing dynasties", in Japanese Studies in the History of Science no. 2 (1963) 94–100.
  2. ^ a b c d e f g Sôma, Mitsuru; Kawabata, Kin-aki; Tanikawa, Kiyotaka (2004-10-25). "Units of Time in Ancient China and Japan". Publications of the Astronomical Society of Japan. 56 (5): 887–904. Bibcode:2004PASJ...56..887S. doi:10.1093/pasj/56.5.887. ISSN 0004-6264. 
  3. ^ "Tiānwén xùn" 天文訓 [Patterns of Heaven], Huainanzi, 日出于暘谷,浴于咸池,拂于扶桑,是謂晨明。
  4. ^ Stephenson, F. Richard; Green, David A. (2002), Historical supernovae and their remnants, Oxford: Oxford University Press, pp. 15–16, ISBN 0-19-850766-6 
  5. ^ Xu Shen, (ed.), "Volume eleven", Shuowen Jiezi, 漏:以銅受水,刻節,晝夜百刻。 Translation: The water clock holds the water in the copper pot, and marks the scale on the rule. There are 100 marks which represent a day. 
  6. ^ a b 曆象彙編/曆法典/第099卷 [Calendar compilations/Calendar quotations/Volume 99], Gujin Tushu Jicheng 
  7. ^ Jean-Claude Martzloff, "Chinese mathematical astronomy", in Helaine Selin, ed., Mathematics across cultures (Dordrecht: Kluwer, 2000) 373–407, p.393, ISBN 0-7923-6481-3
  8. ^ "Taishō Tripiṭaka 1425", Móhēsēngzhī Lǜ 摩訶僧祗律 [Mahāsāṃghika], 須臾者,二十念名一瞬頃,二十瞬名一彈指,二十彈指名一羅豫,二十羅豫名一須臾。日極長時有十八須臾,夜極短時有十二須臾,夜極長時有十八須臾,日極短時有十二須臾。 Rough translation: Definition of xūyú: 20 niàn is 1 shùnqǐng. 20 shùn is 1 tánzhǐ. 20 tánzhǐ is one luóyù. 20 luóyù is one xūyú. In the longest day there are 18 xūyú, and in the shortest night there are 12 xūyú. In the shortest day there are 12 xūyú and in the longest night there are 18 xūyú. 
  9. ^ a b "Zhì dì 14 tiānwén shàng" 志第14 天文上 [Treatise 14, On Astronomy], Book of Sui, "Water clocks" (漏刻), 晝有朝,有禺,有中,有晡,有夕。夜有甲、乙、丙、丁、戊。 Rough translation: Daytime has morning, midmorning, noon, late afternoon, evening. Night has first, second, third, fourth, fifth. 
  10. ^ Petersen, Jens Østergård (1992), "The Taiping Jing and the A.D. 102 Clepsydra Reform", Acta Orientalia, Copenhagen, 53: 122–158